At lightning-base you can do it with just one click.
1. Log into cPanel using https://secure.lightningbase.com/knowledgebase.php?action=displayarticle&catid=4&id=6
2. Click on the domain for which you want to reinstall, under WordPress >> My Application section.
3. Click on Uninstall at the top.
4. After that follow the installation step again as given in the link below
Note : By doing this all the previous content will be lost, the new wordPress installed will be a fresh WordPress installation.